Answer Happy

Model Activity J Structure of Proteins Proteins are polymers of amino acids. Each amino acid contains a carboxylic acid group (-COOH). an amino group (-NH), and a side chain group (R). The amino and side chain groups are bound to an a carbon, the carbon next to the carboxylic acid group. Except for Glycine, alla carbors are chiral. The pH of mout body fluids results in the addition of to the amine (NH) and the loss of H' from the carboxylic acid (COOH). The resulting doubly-Ionized structure is called a witte rion. The 20 different amino acids are classified by the nature of their side chain (R): nonpolar polar, neutral, acidic, and basie a caroon O ũ VÀI HÔI HN- ОН "HN- CH side chain side chain neutral form zwitterion form In a condensation reaction, two amino acids are joined together by a peptide bond and a molecule of H.O is formed. A peptide bond is the formation of an amide functional group from the carboxylic acid group of one amino acid and the amine group of another amino acid. Resonance (the movement of electrons in a molecule) creates partial double bond character for the peptide bond, resulting in restricted rotation "HN-CH -NH-CH=C=0" "HN-CH- -NH-CH- R R peptide bond R double bond R character Further condensation reactions add more amino acids until a polypeptide is formed. The polypeptide chain, with its peptide bonds and sequence of amino acids, is the primary structure of the protein. The secondary structure is created by hydrogen bonds between backbone atoms. Side chain interactions create the tertiary structure.
Part 3: Formation of a Tetrapeptide 1. Combine with another student or group and carry out a condensation reaction with the two dipeptides. Draw the entire structures of the resulting peptide 2. Identify the N terminal and C terminal in the product. 3. Circle all of the R groups in the product.